The Grover® 138 Series deluxe machine heads are mounted three to a plate for the vintage look that has been popular for decades. The stamped back plate provides a sturdy base for mounting vertically or horizontally on the head stock. The housings are securely fastened to the base insuring proper gear and worm alignment for accurate tuning. Bushings and screws included.
Hole Size Required: 8.8mm ~ 3/8"

These guitar machines are a triumph in engineering and styling. The housing provides a maximum bearing for worm, gear and string post. Gear ratio is 14:1. Worm and gear are precision-cut for perfect meshing. This eliminates backlash and slippage. Countersunk tension screw permits player to regulate turning tension to any degree. Gear box has a special lubricant for lifetime, trouble-free service. Includes ⅝" washers, bushings and wood screws.

The 102V series is a remake (replica) of the original “Milk Bottle" style Rotomatics® first introduced by Grover. With an 18:1 gear ratio, this unique style will make any vintage guitar appear truly original.
Package of 6, 3 per side.

Grover 143 Series Lightweight Bass Guitar Machines.
For the ultimate in weight control, Grover offers the 143 series for Bass Guitar. With a plastic housing and aluminum string post, this lightweight bass key is perfect for the player who is concerned about the overall weight of the instrument. The 20:1 gear ratio provides the finest tuning available. Several configurations and are offered, all with a black plastic bass plate and plated button and post.
(Includes: four bushings having an outer diameter of 0.66” and internal M19 x 1.0 threading and four washers).
4 Bass, Set of 4

Grover 143 Series Lightweight Bass Guitar Machines.
For the ultimate in weight control, Grover offers the 143 series for Bass Guitar. With a plastic housing and aluminum string post, this lightweight bass key is perfect for the player who is concerned about the overall weight of the instrument. The 20:1 gear ratio provides the finest tuning available. Several configurations and are offered, all with a black plastic bass plate and plated button and post.
(Includes: four bushings having an outer diameter of 0.66” and internal M19 x 1.0 threading and four washers).
4 Treble, Set of 4